Pocketed-ball snap switch



June 7, 1966 c. B. TERRY 3,255,325

POCKETED-BALL SNAP SWITCH Filed April 17, 1964 INVENTOR. CLIFFORD B- TERRY BY WMJLWF MJ Alfame s United States Patent 3,255,325 POCKETED-BALL SNAP SWITCH Cliiford B. Terry, Huntington, Ind., assignor to Model Engineering & Manufacturing Corp., Huntington, Ind., a corporation of Indiana Filed Apr. 17, 1964, Ser. No. 360,522

2 Claims. (Cl. 200-77) This invention relates generally to electrical switches and more particularly to a low-cost, pocketed-ball snap switch.

Although snap switches are well known and widely used, a need exists for a snap switch capable of being made in extremely small sizes at low cost and possessing reliability of operation.

It is, therefore, a general object of the present invention to provide an improved snap switch.

A further object is to provide a snap switch which can be easily manufactured in very small sizes at low cost and with commonly available materials.

A further object is to provide a snap switch which is easily operated, positive in action, and reliable.

Described briefly, a typical embodiment of the present invention includes a housing having thrust pins or push buttons mounted in opposite walls of the housing. Inside the housing is a cavity enclosing a ball contactor which is movable alternately by one or the other of the two buttons.

A first resilient blade is provided having a portion extending outside the housing for connection with external wiring, and having a U-shaped portion inside the housing formed to provide a detent for an electrical contact ball. This detent is centrally located in the cavity and the electrical contact ball is movable between a switch opening and switch closing position on opposite sides of the detent by alternate actuation of the buttons. As the ball crosses the detent, the resilient blade snaps the ball into one or the other of the switching positions.

A second resilient blade is provided with a portion extending outside the housing for a terminal connection and having a portion inside the housing which is engaged by the contact ball to establish the switch closed position. The portion inside the housing is moved upon actuation of one of the push buttons and is formed so as to return the button to deactuated position when the button is released. i v

The full nature of the invention will be understood from the accompanying drawings and the following descri-ption and claims.

FIG. 1 is an elevational view of the exterior of the switch assembly. I

FIG. 2 is a top plan view thereof. FIG. 3 is an end view thereof.

FIG. 4 is a sectional view taken generally along the :line 4-4 of FIG; 3 and showing the switch in closed position.

FIG. 5 is a sectional view similar to FIG. 4 but showing the switch in open position.

Referring now to the drawings in detail, the switch housing 11 is formed of an upper housing member 12 and a lower housing member 13 which are normally molded in plastic and joined together by cement where they meet at faces 14. As shown in FIG. 1, the housing has a generall H-shape which facilitates its mounting into Patented June 7, 1966 These buttons have coincident or colinear axes and both of them are movable inwardly toward the cavity 23 in the housing by simply applying inwardly directed pressure to the outer ends of the buttons.

A first resilient electrically conductive blade, which may be made of beryllium .copper, for example, has a first portion 24 and a second portion 26 which are parallel to each other inside the cavity and are joined by a transverse portion 27. Any suitable means such as a lug 28, for example, engaging a first wall 29 of the cavity can be used to prevent the first blade from moving away from the second wall 31 which supports the transverse portion 27 of the blade.

As shown in FIG. 5, a contact ball 32 is disposed in the cavity 23 and is engaged by the hump 34 at the free end of the blade at the point 36. The blade is under stress in this position and thus biases the ball against the inner end of the button 17 and against the fourth wall 37 of the cavity. The solid line position of the ball in FIG. 5 is the position assumed by the ball when the switch is open. Because the ball is trapped between the inner end of the button, the wall 37 of the cavity and the hump in the resilient blade, the switch will remain securely in open condition until the button 17 is pushed inwardly through the position indicated by broken lines in FIG.

The first blade extends outwardly through the housing to the exterior thereof toprovide a terminal portion 39 to which external wiring can be connected. A second resilient blade is also provided in the assembly and it too has a terminal portion 41 at the outside of the housing. This second blade has a first portion 42 in the cavity extending transversely to the common axis of the buttons, a second curved portion 44 in the cavity, and a third portion 46 extending through a wall of the housing to the terminal portion 41. Any suitable means such as lugs 47 and 48 pressed out of the blade for engagement with a the housing walls may be used to prevent movement of the portion 46 in the housing.

The curved portion 44 of the blade is under stress and normally maintains the end of the second blade firmly engaged with the button 16, holding the button flange against the wall 29 of the housing. As soon as the ball 32 is pressed by button 17 against the force exerted by the first blade across the crest 49 of the hump 34, the restoring force created by distortion of the blade assists the original biasing force in the blade to snap the ball into its solid line position of FIG. 4 against the first portion 42 of the second blade. The ball is then securely trapped in this position by the hump 34, the blade portion 42, and the wall 37. It will remain in this position until the button 16 is pushed inwardly to again snap the ball past the crest 49- into its original position. When the ball is in the position shown in FIG. 4,

it completes an electrical path from the terminal portion 39 to the terminal portion 41. Again it should be noted that while the portion 44 of the second blade is elfective to normally keep the button 16 in the position shown in FIGS. 4 and 5, it does accommodate sufficient inward movement of the button 16 to force the ball past the crest 49 so that the first blade may snap the ball into its solid line' position of FIG. 5. -Then, when the button 16 is released, the second blade will return it to its original position. This switch is typically manufactured in dimensions 0 the order of one-half inch by one-half inch by one-quarter inch. Yet, because of its novel construction, it can be manufactured in such small sizes at low cost and still provide reliable operation over a long period of time. It should be noted that as the contact ball 32 is moved by the button 16 to open the switch, cont-act pressure increases during the transitional period prior to the snapover of the ball.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A switch comprising:

a closed housing of electrically non conducting material, said housing having a cavity therein and having a first aperture in a first wall thereof and a second aperture in a second wall opposite said first wall, said apertures being cylindrical and having colinear axes;

a first cylindrical push button slidably received in said first aperture and having one end projecting out of said housing and having first stop means on the other end, said first stop means being abutingly engageable with a surface of said first Wall in said cavity to limit travel of said button;

a second cylindrical push button slidably received in said second aperture and having one end projecting out of said housing and having second stop means on the other end, said second stop means being abuttingly engageable with a surface of said second wall in said cavity to limit travel of said second button;

a first electrically conductive resilient blade having first and second parallel portions joined by a transverse portion to form a U-shaped bend in said cavity with said first portion resting against a third wall of said cavity and supported thereby and extending outside of said housing to provide a first electrical connector terminal;

the second portion of said first blade having a free end in said cavity and a hump projecting toward said aperture axes and toward a fourth wall of said cavity, said fourth wall facing said third wall and said axes passing between said third and fourth walls and gen I er-ally parallel thereto;

a second electrically conductive resilient blade having first, second, and third portions, with said first portion and said third portion being disposed in perpendicular planes and joined by said second portion, said second portion having a curved configuration;

the first portion of said second blade being disposed in said cavity and movable by the inner end of said first button when said first button is moved inwardly with respect to said cavity, the motion of said inner end being accommodated by fiexure of said curved secend portion;

the third portion of said second blade being fixed in said housing and extending outside of said housing to provide a second electrical connector terminal;

an electrically conductive contact ball in said cavity, said ball having a first position engaging said hump and resiliently forced thereby against said fourth Wall and the inner end of said second button;

inward movement of said second button being operable to displace said ball parallel to said axes and against the resilient bias of said first blade and over the crest of said hump to a second position wherein said ball is held by said hump against said fourth wall and said first portion of said second blade to make an electrical path from said first blade to said second blade through said ball;

inward movement of said first button when said ball is in said second position being operable to return the ball parallel to said axes and against the bias of said first blade and over the crest of said hump to said first position to break said electrical path;

the restoring force developed in said first blade as said ball is moved toward the crest of said hump being 4 operative when said ball passes the crest of said hump to snap the ball into position;

the restoring force developed in said second blade by its fiexure upon inward motion of said first button returning said first button to its original position.

2, A switch comprising:

a housing having a cavity therein and having a first aperture in a first wall thereof and a second aperture in a second wall opposite said first wall, said apertures having colinear axes, and said cavity having a branch therein extending perpendicular to said axes;

a first push button slidably received in said first aperture and having one end projecting out of said housa second push button slidably received in said second aperture and having one end projecting out of said housing;

a first resilient blade having first and second parallel portions joined by a transverse portion to form a U- shaped bend in said cavity with said first portion resting against a third wall of said cavity and supported thereby and extending outside of said housing to provide a first electrical connector terminal;

the second portion of said first blade having a free end in said cavity and a hump projecting toward said aperture axes and toward a fourth wall of said cavity, said fourth wall facing said third wall and said axes passing between said third and fourth Walls;

a second resilient blade having first, second, and third portions, with said first portion and said third portion being joined by said second portion, said second portion having a curved configuration;

the first portion of said second blade being disposed in said cavity and movable by the inner end of said first button when said first button is moved inwardly with respect to said cavity, the motion of said inner end being accommodated by fiexure of said curved second portion;

the third portion of said second blade extending outside of said housing to provide a second electrical connector terminal;

a contact ball in said cavity, said ball having a first position engaging said hump and resiliently forced thereby against said fourth wall and the inner end of said second button;

inward movement of said second button being operable to displace said ball in a direction generally parallel to said axes and against the resilient bias of said first blade and over the crest of said hump to a second position wherein said ball is held by said hump against said fourth wall and said first portion of said second blade to make an electrical path from said first blade to said second blade through said ball;

inward movement of said first button when said ball is in said second position being operable to return the ball against the bias of said first blade and over the crest of said hump to said first position to break said electrical path;

the restoring force developed in said first blade as said ball is moved toward the crest of said hump being operative when said ball passes the crest of said hump to snap the ball into position; i

the restoring force developed in said second blade by its fiexure upon inward motion of said first button returning said first button to its original position.

References Cited by the Examiner UNITED STATES PATENTS KATHLEEN H. CLAFFY, Primary Examiner. D. SMITH, Assistant Examiner. 

1. A SWITCH COMPRISING: A CLOSED HOUSING A ELECTRICALLY NON CONDUCTING MATERIAL, SAID HOUSING HAVING A CAVITY THEREIN AND HAVING A FIRST APERTURE IN A FIRST WALL THEREOF AND A SECOND APERTURE IN A SECOND WALL OPPOSITE SAID FIRST WALL, SAID APERTURES BEING CYLINDRICAL AND HAVING COLINEAR AXES; A FIRST CYLINDRICAL PUSH BUTTON SLIDABLY RECEIVED IN SAID FIRST APERTURE AND HAVING ONE END PROJECTING OUT OF SAID HOUSING AND HAVING FIRST STOP MEANS ON THE OTHER END, SAID FIRST STOP MEANS BEING ABUTINGLY ENGAGEABLE WITH A SURFACE OF SAID FIRST WALL IN SAID CAVITY TO LIMIT TRAVEL OF SAID BUTTON; A SECOND CYLINDRICAL PUSH BUTTON SLIDABLY RECEIVED IN SAID SECOND APERTURE AND HAVING ONE END PROJECTING OUT OF SAID HOUSING AND HAVING SECOND STOP MEANS ON THE OTHER END, SAID SECOND STOP MEANS BEING ABUTTINGLY ENGAGEABLE WITH A SURFACE OF SAID SECOND WALL IN SAID CAVITY TO LIMIT TRAVEL OF SAID SECOND BUTTON; A FIRST ELECTRICALLY CONDUCTIVE RESILIENT BLADE HAVING FIRST AND SECOND PARALLEL PORTIONS JOINED BY A TRANSVERSE PORTION TO FORM A U-SHAPED BEND IN SAID CAVITY WITH SAID FIRST PORTION RESTING AGAINST A THIRD WALL OF SAID CAVITY AND SUPPORTED THEREBY AND EXTENDING OUTSIDE OF SAID HOUSING TO PROVIDE A FIRST ELECTRICAL CONNECTOR TERMINAL; THE SECOND PORTION OF SAID FIRST BLADE HAVING A FREE END IN SAID CAVITY AND A HUMP PROJECTING TOWARD SAID APERTURE AXES AND TOWARD A FOURTH WALL OF SAID CAVITY, SAID FOURTH WALL FACING SAID THIRD WALL AND SAID AXES PASSING BETWEEN SAID THIRD AND FOURTH WALLS AND GENERALLY PARALLEL THERETO; A SECOND ELECTRICALLY CONDUCTIVE RESILIENT BLADE HAVING FIRST, SECOND, AND THIRD PORTIONS, WITH SAID FIRST PORTION AND SAID THIRD PORTION BEING DISPOSED IN PERPENDICULAR PLANES AND JOINED BY SAID SECOND PORTION, SAID SECOND PORTION HAVING A CURVED CONFIGURATION; THE FIRST PORTION OF SAID SECOND BLADE BEING DISPOSED IN SAID CAVITY AND MOVABLE BY THE INNER END OF SAID FIRST BUTTON WHEN SAID FIRST BUTTON IS MOVED INWARDLY WITH RESPECT TO SAID CAVITY, THE MOTION OF SAID INNER END BEING ACCOMMODATED BY FLEXURE OF SAID CURVED SECOND PORTION; THE THIRD PORTION OF SAID SECOND BLADE BEING FIXED IN SAID HOUSING AND EXTENDING OUTSIDE OF SAID HOUSING TO PROVIDE A SECOND ELECTRICAL CONNECTOR TERMINAL; AN ELECTRICALLY CONDUCTIVE CONTACT BALL IN SAID CAVITY, SAID BALL HAVING A FIRST POSITION ENGAGING SAID HUMP AND RESILIENTLY FORCED THEREBY AGAINST SAID FOURTH WALL AND THE INNER END OF SAID SECOND BUTTON; INWARD MOVEMENT OF SAID SECOND BUTTON BEING OPERABLE TO DISPLACE SAID BALL PARALLEL TO SAID AXES AND AGAINST THE RESILIENT BIAS TO SAID FIRST BLADE AND OVER THE CREST OF SAID HUMP TO A SECOND POSITION WHEREIN SAID BALL IS HELD BY SAID HUMP AGAINST SAID FOURTH WALL AND SAID FIRST PORTION OF SAID SECOND BLADE TO MAKE AN ELECTRICAL PATH FROM SAID FIRST BLADE TO SAID SECOND BLADE THROUGH SAID BALL; INWARD MOVEMENT OF SAID FIRST BUTTON WHEN SAID BALL IS IN SAID SECOND POSITION BEING OPERABLE TO RETURN THE BALL PARALLEL TO SAID AXES AND AGAINST THE BIAS OF SAID FIRST BLADE AND OVER THE CREST OF SAID HUMP TO SAID FIRST POSITION TO BREAK SAID ELECTRICAL PATH; THE RESTORING FORCE DEVELOPED IN SAID FIRST BLADE AS SAID BALL IS MOVED TOWARD THE CREST OF SAID HUMP BEING OPERATIVE WHEN SAID BALL PASSES THE CREST OF SAID HUMP TO SNAP THE BALL INTO POSITION; THE RESTORING FORCE DEVELOPED IN SAID SECOND BLADE BY ITS FLEXURE UPON INWARD MOTION OF SAID FIRST BUTTON RETURNING SAID FIRST BUTTON TO ITS ORIGINAL POSITION. 